U.S. patent number 6,381,981 [Application Number 09/847,902] was granted by the patent office on 2002-05-07 for container for shipping and storing frozen products.
This patent grant is currently assigned to Advanced Tissue Sciences, Inc.. Invention is credited to Charles Bankert, Stephen Kemmerrer, Jerry Yaddgo.
United States Patent |
6,381,981 |
Yaddgo , et al. |
May 7, 2002 |
Container for shipping and storing frozen products
Abstract
The present invention is directed to a container and method for
shipping and storing frozen products. In particular, the present
invention is directed to an insulated container for shipping and
storing frozen tissue samples for an extended period of time, for
example at least 72 hours. An exemplary embodiment of the container
of the present invention includes a body having an open end and a
product chamber lined with vacuum insulated panels, a spring
assembly inside of the product chamber for supporting a lower
cooling block and a stack of tissue packages (e.g. engineered
tissue samples), and a lid assembly including one or more upper
cooling blocks suspended therefrom. When the lid assembly is
secured on the body of the container, the tissue packages are held
in place between the upper and lower cooling blocks by the force of
the spring assembly. The body of the container is dimensioned so
that it may fit within an outer cardboard carton if desired for
shipping.
Inventors: |
Yaddgo; Jerry (Lakeside,
CA), Kemmerrer; Stephen (San Diego, CA), Bankert;
Charles (Oceanside, CA) |
Assignee: |
Advanced Tissue Sciences, Inc.
(La Jolla, CA)
|
Family
ID: |
25301774 |
Appl.
No.: |
09/847,902 |
Filed: |
May 2, 2001 |
Current U.S.
Class: |
62/372;
62/457.2 |
Current CPC
Class: |
F25D
3/125 (20130101); A61B 50/00 (20160201); A61J
1/165 (20130101); F25D 3/08 (20130101); F25D
2201/14 (20130101); F25D 2303/082 (20130101); F25D
2331/804 (20130101); A61B 2050/0014 (20160201) |
Current International
Class: |
A61B
19/00 (20060101); A61B 19/02 (20060101); F25D
3/12 (20060101); F25D 3/00 (20060101); A61J
1/16 (20060101); A61J 1/14 (20060101); F25D
3/08 (20060101); F25D 003/08 () |
Field of
Search: |
;62/239,457.1,457.2,372,457.7 ;220/559,578 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tapolcai; William E.
Assistant Examiner: Ali; Mohammad M
Attorney, Agent or Firm: Pennie & Edmonds LLP
Claims
What is claimed is:
1. A container for shipping and storing frozen products,
comprising:
a body having a product chamber and an open end, the product
chamber having a shape adapted to receive a product disposed
between a first cooling element and a second cooling element;
a lid assembly adapted to sealingly engage the open end of the
body; and
a first spring assembly positioned within said product chamber,
said first spring assembly adapted to bias the first cooling
element toward the second cooling element when the lid assembly
engages the body, such that the product is held between the first
cooling element and the second cooling element.
2. The container of claim 1, wherein said lid assembly includes a
restraint for suspending the second cooling element therefrom when
said lid assembly is removed from said body.
3. The container of claim 2, wherein the restraint is a net
suspended from a bottom surface of said lid assembly, such that the
net and the second cooling element enter the product chamber when
said lid assembly engages said body.
4. The container of claim 1, wherein the body includes at least one
side wall defining a side of the product chamber and a bottom lid
defining a bottom of the product chamber opposite the open end.
5. The container of claim 4, wherein said side wall and said bottom
lid are comprised of polystyrene.
6. The container of claim 4, wherein said first spring assembly is
disposed between said bottom lid and the first cooling element.
7. The container of claim 6, further comprising a second spring
assembly disposed in said product chamber between said lid assembly
and the second cooling element when said lid assembly engages the
open end of the body, such that the first and second cooling
elements and the product are disposed between the first spring
assembly and the second spring assembly.
8. The container of claim 4, wherein said first spring assembly is
disposed between said lid assembly and the second cooling element
when said lid assembly engages the open end of the body.
9. The container of claim 4, wherein said first spring assembly is
disposed between said side wall and the first cooling element, such
that said first spring assembly biases the first cooling element in
a direction orthogonal to the open end of the body.
10. The container of claim 9, further comprising a second spring
assembly disposed in said product chamber, said second spring
assembly adapted to oppose the first spring assembly and bias the
second cooling element toward the first cooling element.
11. The container of claim 4, wherein:
said body further includes an inner container comprising at least
one side panel disposed between said side wall and the product
chamber and a bottom panel disposed between the bottom lid and the
product chamber; and
said lid assembly includes a lid panel adapted to sealingly engage
said inner container when said lid assembly engages said body.
12. The container of claim 11, wherein said side panel, bottom
panel, and lid panel are vacuum insulated panels.
13. The container of claim 12, further comprising:
a bottom gasket disposed between a bottom edge of said side panel
and said bottom panel; and
a top gasket disposed between a top edge of said side panel and
said lid panel when said lid panel sealingly engages said side
panel.
14. The container of claim 11, further comprising a liner
separating said product chamber from said inner container.
15. The container of claim 11, wherein said first spring assembly
is disposed between said lid panel and the second cooling element
when said lid assembly engages the open end of the body.
16. The container of claim 11, wherein said first spring assembly
is disposed between said bottom panel and the first cooling
element.
17. The container of claim 16, wherein said first spring assembly
comprises a top plate, a bottom plate and a spring member attached
to and disposed between said top and bottom plates, said top plate
positioned toward the open end of said body and adapted to support
the first cooling element.
18. The container of claim 17, wherein said top plate includes a
locating clip adapted to hold said first cooling element in a
position on said top plate.
19. The container of claim 18, further comprising:
the first cooling element disposed in said product chamber on said
top plate of said first spring assembly;
the second cooling element disposed in said product chamber
adjacent to said lid assembly; and
the product disposed in said product chamber and held between the
first cooling element and the second cooling element.
20. The container of claim 19, wherein said second cooing element
is held within a restraint attached to said lid assembly, such that
said second cooling element is removed from said product chamber
when said lid assembly is removed from said body.
21. The container of claim 20, wherein said restraint is a net
attached to said lid assembly, wherein a portion of said net
contacts said product and is between said second cooling element
and said product when said lid assembly engages said body.
22. The container of claim 1, further comprising a shipping carton
into which the body is received.
23. The container of claim 1, wherein said product is maintained at
or below a temperature of -65.degree. C. in said container for at
least 72 hours.
24. The container of claim 1, wherein said product is maintained at
or below a temperature of -65.degree. C. in said container for at
least 96 hours.
25. The container of claim 1, wherein said product is maintained at
or below a temperature of -65.degree. C. in said container for at
least 120 hours.
26. The container of claim 1, wherein the product is at least one
frozen tissue.
27. A container for shipping and storing frozen products,
comprising:
an body having a product chamber and an open end,
a lid assembly adapted to sealingly engage the open end of the
body;
at least one product disposed in said product chamber between a
first cooling element and a second cooling element;
a first spring assembly disposed in said product chamber, wherein
said first spring assembly biases the first cooling element toward
the second cooling element when the lid assembly engages the body,
such that said product is held between the first cooling element
and the second cooling element.
28. The container of claim 27, further comprising a plurality of
products disposed between the first and second cooling
elements.
29. The container of claim 27, wherein a restraint attaches said
second cooling element to said lid assembly.
30. The container of claim 27, wherein said first spring assembly
is disposed between said lid assembly and said second cooling
element when said lid assembly engages the open end of the
body.
31. The container of claim 27, wherein:
said body comprise at least one side panel defining a side of the
product chamber and a bottom panel defining a bottom of the product
chamber opposite the open end; and
said lid assembly comprises a lid panel configured to sealingly
engage said side panel when said lid assembly engages the open end
of the body.
32. The container of claim 31, wherein said side panel, bottom
panel, and lid panel are vacuum insulated panels.
33. The container of claim 31, wherein said first spring assembly
is disposed between said bottom panel and the first cooling
element, such that said first spring assembly biases the first
cooling element against the product and the product against the
second cooling element.
34. The container of claim 33, wherein said first spring assembly
comprises a top plate, a bottom plate and a spring member attached
to and disposed between said top and bottom plates, said top plate
positioned toward the open end of said body and supporting said
first cooling element.
35. The container of claim 34, wherein said top plate includes a
locating clip adapted to hold said first cooling element in a
position on said top plate.
36. The container of claim 33, wherein said second cooing element
is held within a restraint attached to said lid assembly, such that
said second cooling element is removed from said product chamber
when said lid assembly is removed from said body.
37. The container of claim 36, wherein said restraint is a net
attached to said lid assembly, and wherein a portion of said net
contacts said product and is between said second cooling element
and said product when said lid assembly engages said body.
38. The container of claim 31, wherein said first spring assembly
is disposed between said side panel and the first cooling element,
such that said first spring assembly biases the first cooling
element against the product in a direction orthogonal to the open
end of said body.
39. The container of claim 38, further comprising a second spring
assembly disposed in said product chamber, said second spring
assembly adapted to oppose the first spring assembly and bias the
second cooling element toward the first cooling element.
40. The container of claim 27, further comprising a shipping carton
into which the body is received.
41. The container of claim 27, wherein said product is maintained
at or below a temperature of -65.degree. C. in said container for a
duration of at least 72 hours.
42. The container of claim 27, wherein said product is maintained
at or below a temperature of -65.degree. C. in said container for
at least 96 hours.
43. The container of claim 27, wherein said product is maintained
at or below a temperature of -65.degree. C. in said container for
at least 120 hours.
44. The container of claim 27, wherein the product is at least one
frozen tissue.
45. A container for shipping and storing frozen products,
comprising:
a body having an open end and a product chamber defined by at least
one wall;
a door assembly adapted to sealingly engage the open end of the
body;
at least one product disposed in said product chamber between a
first cooling element and a second cooling element;
a first spring assembly disposed in said product chamber between
the first cooling element and the wall of the product chamber;
and
a second spring assembly disposed in said product chamber and
adapted to bias the second cooing element toward the first cooling
element, such that the product is held between the first and second
cooling elements.
46. A container according to claim 45, wherein the product chamber
is further defined by a second wall, and the second spring assembly
is disposed between the second wall and the second cooling
element.
47. The container of claim 46, wherein:
the first spring assembly provides a first biasing force in a
direction orthogonal to the open end of the body,
the second spring assembly provides a second biasing force opposing
the first biasing force, and
the product is held between the first and second cooling elements
by the first and second biasing forces.
48. The container of claim 45, further comprising a plurality of
products disposed between the first and second cooling
elements.
49. The container of claim 45, wherein:
said body comprises at least one side panel lining the product
chamber; and
said door assembly comprises at least one door panel that sealingly
engages the side panel when said door assembly engages said
body.
50. The container of claim 45, wherein said side panel and said
door panel are vacuum insulated panels.
51. The container of claim 45, wherein:
said first spring assembly comprises a first top plate, a bottom
plate and a spring member attached to and disposed between said top
and bottom plates, said top plate adjacent to said first cooling
element.
52. The container of claim 51, wherein said top plate includes a
locating clip adapted to hold said first cooling element in a
position on said top plate.
53. The container of claim 45, further comprising a shipping carton
into which the body is received.
54. The container of claim 45, wherein said product is maintained
at or below a temperature of -65.degree. C. in said container for a
duration of at least 72 hours.
55. The container of claim 45, wherein said product is maintained
at or below a temperature of -65.degree. C. in said container for
at least 96 hours.
56. The container of claim 45, wherein said product is maintained
at or below a temperature of -65.degree. C. in said container for
at least 120 hours.
57. The container of claim 45, wherein said product is at least one
frozen tissue.
Description
TECHNICAL FIELD
The present invention relates generally to a container for shipping
and storing temperature-sensitive products, and in particular to a
container for maintaining frozen tissues and other products during
shipping and storage.
BACKGROUND OF THE INVENTION
Currently available containers for transporting frozen or
refrigerated products generally include a cardboard shipping carton
lined with insulating material such as such as expanded polystyrene
(EPS), polyurethane or other foam material. The insulating material
may be in the shape of modular panels or, for example, may be
injection molded into any desired shape. The insulation typically
defines a central cavity where products are stored along with a
coolant, such as ice packs or loose blocks of dry ice. A plug, such
as a thick polyester or polyether foam pad, is generally placed
over the top of the product before the carton is closed and
prepared for shipping.
Such conventional shipping containers have many limitations,
particularly when shipping or storing sensitive frozen products,
such as sterile frozen tissue samples, for extended periods of
time. For example, engineered tissue implants, must be maintained
in a sterile condition at or below approximately -65.degree. C. for
a number of days during transcontinental or international shipping,
particularly in the case of shipping delays or extended storage.
Conventional containers simply are not adequately insulated or
designed to maintain such products at low temperatures for more
than one or two days. While increasing the thickness and/or number
of layers of insulating material may aid in extending product
maintenance time, the resulting increase in size and cost of such a
shipping container is typically prohibitive.
Another problem with conventional shipping containers is that they
fail to provide constant, evenly distributed contact between
coolant and product. Such constant contact and even distribution of
the coolant is desirable for maintaining frozen products over an
extended period of time. In typical shipping containers, however,
products and/or coolant blocks often shift during shipping and
handling, resulting in a loss of contact or a change in the
distribution of coolant. Such shifting is increasingly problematic
during extended periods when the coolant decreases in size as it
melts or sublimates, or if a recipient removes a portion of the
product and wishes to maintain the rest in the container. Shifting
of contents during transport may also result in damage to the
product, its packaging or labeling, and may compromise product
sterility. Additionally, in situations where a coolant block is
placed on top of a product, conventional containers require a
recipient to handle the block to access the product, possibly
resulting in injury to the recipient or damage to the product.
Accordingly, there remains a need in the art for a improved
container for shipping and storing varying amounts of frozen
products at low temperatures for extended periods of time, while
minimizing overall size and weight of the container.
SUMMARY OF THE INVENTION
The present invention is directed to a container for shipping and
storing frozen products. In particular the present invention is
directed to an insulated container for shipping and storing frozen
tissue samples for an extended period of time. An exemplary
embodiment of the container of the present invention includes a
body having an open end and a product chamber, a spring assembly
inside of the product chamber for supporting a cooling block and
one or more packages of tissue (e.g. engineered tissue samples),
and a lid assembly including one or more cooling blocks suspended
therefrom that contact at least one of the tissue packages when the
lid assembly is placed over the open end of the container body. The
body of the container is dimensioned to fit within an outer
container for shipping.
In the above-described exemplary embodiment, the body of the
container includes an inner container and an outer container. The
outer container is in the shape of an open box, with four side
walls and a bottom lid of insulated foam material, such as EPS,
polyurethane or any other rigid or soft foam. The inner surface of
the walls and bottom of the outer container are lined with four
vacuum insulated side panels and a bottom panel that comprise the
inner container and define the product chamber. In certain
embodiments, the outer and/or inner container have more than four
walls, such that the body and/or product chamber is hexagonal,
octagonal or the like. In certain other embodiments, the outer
and/or inner containers may have less than four walls, such that
the body and/or product chamber is triangular, cylindrical,
elliptical, etc.
In an exemplary embodiment, a gasket is disposed between the bottom
edge of the side panels and the bottom panel to reduce air flow in
or out of the chamber. Adjacent side panel are beveled to ensure a
tight seal. Optionally, panels may be configured, attached or
sealed in any manner to minimize leaks between adjacent panels.
Optionally, the product chamber is lined with a single or double
layer of corrugated cardboard or similar material to protect the
vacuum panels.
The spring assembly of this exemplary embodiment fits in the bottom
of the product chamber and has a resilient spring member disposed
between two plates, a bottom plate and a top plate. The bottom
plate rests against, and is optionally attached to, the bottom of
the product chamber. The top plate faces the open end of the
chamber, and is adapted to support the lower cooling block and the
stack of tissue samples. A clip is added to the top plate to
maintain the coolant on the center of the product. The clip anchors
and positions the coolant on the center/main mass of the product
and prevents the coolant from shifting, particularly when the
shipper is laid on its side. When the lid assembly is placed over
the body, the stack of tissue samples is held between the upper and
lower cooling blocks by the force of the spring. The spring has
enough travel to assure forceful contact regardless of the quantity
of product being shipped and to allow for sublimation of the dry
ice during shipping and storage. In an alternative embodiment, the
spring assembly is positioned above the product, for example it may
be attached to the lid assembly.
The lid assembly of the above-described exemplary embodiment
includes a top lid, a top vacuum panel, and a restraint for
suspending the upper cooling block(s). When placed over the body,
the restraint is disposed within the product chamber, the top panel
mates with the inner chamber, and the top lid mates with the outer
chamber. The elements of the lid assembly are attached for ease of
removal, such that a recipient of the container need not touch the
cooling blocks to access the tissue samples. A strap is optionally
provided to aid in the removal of the lid assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the nature and details of the
invention, reference should be made to the following detailed
description taken in conjunction with the accompanying drawings, in
which:
FIG. 1 is an exploded side view of an exemplary embodiment of the
shipping container of the present invention;
FIG. 2A is a cross-sectional side view of the shipping container of
FIG. 1, shown in an open configuration;
FIG. 2B is a cross-sectional side view of the shipping container of
FIG. 1, shown in a closed configuration;
FIG. 3 is side view of an alternative embodiment of a shipping
container according to the present invention;
FIG. 4 is a graph showing results of a thermal bench test of an
exemplary shipping container according to FIG. 1;
FIG. 5 is a graph showing results of a cooler test of an exemplary
shipping container according to FIG. 1;
FIG. 6 is a graph showing results of a shock and vibration test of
an exemplary shipping container according to FIG. 1;
FIG. 7 is a graph showing temperature of products over time in a
conventional shipping container laying on its side;
FIG. 8 is a graph showing temperature of products over time in a
conventional shipping container, as the container is periodically
rotated;
FIG. 9 is a graph showing temperature of products over time in a
shipping container including a spring assembly according to the
present invention; and
FIG. 10 is a graph showing temperature of products over time in a
shipping container including a spring assembly and vacuum panels
according to the present invention.
Like reference numerals refer to corresponding parts throughout the
several views of the drawings.
DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show an exemplary embodiment of a container 10 for
shipping frozen tissues according to the present invention.
Container 10 generally includes a body 20, a spring assembly 50, a
lid assembly 40 and an outer carton 80. As best shown in FIG. 2A,
body 20 includes an open product chamber 70 for holding spring
assembly 50, one or more products 72 (e.g. packages of frozen
tissue), and one or more cooling members, or blocks 60. Lid
assembly also includes one or more cooling blocks 62 suspended
within a restraint 46. When lid assembly is placed over the open
end of container body 20 as shown in FIG. 2B, product 72 is held
tightly between upper cooling block 62 and lower cooling block 60
by a biasing force of spring assembly 50. Upper cooling block 62
and lower cooling block 60 are both typically, although not
necessarily, dry ice.
Container body 20 includes an outer container 22 and an inner
container 30. Outer container 22 has four side walls 24 and a
bottom lid 26, arranged to form the shape of an open square or
rectangular box. Alternatively, outer container 22 may have any
number of side walls arranged to form any desired shape, such as a
cylinder. Side walls 24 and bottom lid 26 are constructed of
styrofoam panels that are dimensioned and arranged to line the
interior of carton 80. In certain embodiments, side walls 24 and
bottom lid 26 are interlocking expanded polystyrene (EPS) panels
having a thickness of 0.5 to 2.0 inches. In other embodiments, the
thickness is about 1.0 inch. Alternatively, polyurethane foam or
other material having suitable insulating properties may be used to
line carton 80 and form outer container 22. As is best shown in
FIG. 2A, each side wall 24 includes notches 25, 27 along its upper
edge and lower edge, respectively. When side walls 24 are fitted
together, notches 27 form a ledge that is dimensioned to mate with
bottom lid 26, and notches 25 form a ledge that is dimensioned to
mate with lid assembly 40. One skilled in the art will appreciate
that the walls 24 may be dimensioned and configured in various ways
to line the interior of carton 80 without departing from the scope
of the invention. For example, in an alternative embodiment of the
invention, outer container 22 is a single body comprised of side
walls and a bottom wall constructed of injection molded EPS (not
shown).
Referring again to FIG. 2A, inner container 30 is comprised of four
side panels 32 and a bottom panel 34 that line the interior
surfaces of outer container 22 and define product chamber 70.
Panels 32 and 34 are insulated panels such as vacuum insulated
panels comprising a core material (e.g. DOW INSTILL HT, INSTILL UC,
INSTILL AF or similar core material) and a barrier film (e.g. a
mylar barrier film such as DUPONT MYLAR 22RS BL300, MYLAR 250 RS
BL300, MYLAR 350 RS BL300, or similar material). Panels 32 and 34
of the present embodiment have a thickness of approximately 1.0
inch, but other thicknesses (e.g., 0.25-2.0 inches) may be used
depending upon the desired insulation properties and overall size
and weight of container 10. Each side panel 32 may be beveled along
its side edges (not shown) to form a tight joint between adjacent
panels. One skilled in the art will appreciate that adjacent panels
may be connected or joined in any manner to ensure a tight seal,
and may be dimensioned and arranged in any fashion to give the
product chamber a desired size and shape.
Optionally, a thin gasket 36 is disposed between the bottom end of
each side panel 32 and bottom panel 34, as shown in FIGS. 2A and
2B. Gasket 36 is shaped and dimensioned in any fashion suitable for
creating a seal between panels 32 and 34, such as a rectangular
ring. Gasket 36 is comprised of polyethylene or any other
compressible material suitable for creating a seal between panels
32 and 34 in order to limit air flow into an out of chamber 70.
Body 20 of shipping container 10 optionally includes a protective
liner 74 inside chamber 70 to protect panels 32 and 34 from contact
by spring assembly 50, product packages 72, cooling blocks 60, 62
or other contents of chamber 70. Protective liner may be of any
material suitable for protecting panels and/or providing additional
insulation, such as single or double-walled corrugated cardboard or
foam.
Like body 20, lid assembly 40 generally comprises two layers of
insulating material: top lid 42 and top panel 44. Top lid 42 is
configured and dimensioned essentially the same as bottom lid 26,
and is comprised of the same material as outer container 22 (e.g.,
EPS foam or other foam material). One or more corners 43 of lid 42
may be cut or notched to facilitate removal of lid assembly 40.
Top panel 44 is a vacuum panel comprised of the same material as
inner container 30 (e.g., DOW INSTILL core material with DUPONT
mylar polyester barrier films as described above) and dimensioned
approximately the same as bottom panel 34. Top lid 42 and top panel
44 are attached together, for example by adhesive material such as
tape, glue or epoxy or by straps, staples, screws or any other
attachment means. In an alternative embodiment of the shipping
container of the present invention, top lid and top panel are not
attached together. In yet another alternative embodiment, top lid
and top panel are not distinct elements, rather lid assembly is
comprised of a single injection molded top lid having shaped plug
(not shown) that fits within cavity 70 when the lid assembly is
placed on body 20.
A cooling block restraint 46, such as a net comprised of
polyethylene, nylon or other suitable material, is attached to lid
assembly 40. Restraint may be secured between top panel 44 and top
lid 42, or may be attached directly to top panel 44 or top lid 42
using any suitable adhesive or other attachment means, such as
tape, glue, epoxy, staples, brads, screws, etc. Restraint 46 is of
such size and strength as to hold one or more cooling blocks 62
(e.g. dry ice) suspended from lid assembly 22 when assembly 22 is
removed from body 20 of container 10. For example, the embodiment
of FIGS. 1 and 2 uses an approximately 24 inch, heat-sealed
polyethylene net 46 (NSW Corporation, Roanoke, Va.).
A band 48, such as a band of rubber, silicone or other elastic
material, is placed around net 46 and cooling blocks 62 to gather
any excess material and prevent it from interfering with the seal
between lid assembly 40 and body 20 when container 10 is closed.
Band 48 also aids in centering upper blocks 62 over product 72
within chamber 70. Restraint 46 allows a customer or other user of
shipping container to access product 72 without handling cooling
blocks 62. Restraint 46 also ensures replacement of upper cooling
blocks 62 when lid is returned, thereby ensuring that thermal
performance of container 10 is maintained for continued storage of
any remaining any product 72.
As shown in FIG. 1, a strap 49 is optionally attached to lid
assembly 40 to facilitate placement and removal of lid assembly.
For example, strap 49 may be a loop of nylon, cotton, rubber,
plastic or any other material of suitable strength wrapped around
top lid and/or secured between top lid and top panel.
Lower block 60 and upper blocks 62 of FIGS. 2A and 2B are typically
dry ice, for example, with dimensions of approximately
5".times.7".times.1.7". However, one skilled in the art will
appreciate that various sizes and numbers of blocks may be used
depending, for example, upon the size and characteristics of the
shipping container, the 20 type and amount of product to be shipped
or stored, the desired temperature of the product and the desired
duration of storage. Alternatively, other cooling elements, such as
ice bags, gel packs, freezer blocks, liquid nitrogen containers, or
the like may be used.
Spring assembly 50 includes a spring member 52 disposed between top
plate 54 and bottom plate 56. Spring member 52 is a coil
compression spring constructed of metal, plastic, or other
material. In an exemplary embodiment, spring member 52 is a 0.135"
wire compression spring having an outside diameter of approximately
4.25", a free length of approximately 7.0" and a fully compressed
height of less than 1.0" under a load of 12-15 lbs. Naturally,
other spring sizes and configurations may be used without departing
from the scope of the invention. Similarly, the strength of spring
member 52 may vary depending, at least in part, upon the size of
the container, the amount of product to be shipped and/or stored,
and the weight of the cooling blocks.
One skilled in the art will appreciate that maximum load of spring
member 52 generally should be greater than the weight of the
contents of the container (e.g. product 72 plus cooling blocks 60,
62), however not so great as to damage product 72 or prevent
sealing of container 10 when lid assembly 40 is placed on body 20.
Other suitable types of springs include, but are not limited to,
compression and extension springs, constant force wire springs,
wave, finger and curved springs, die springs, Belleville disc
springs and torsion springs. Alternatively, other devices or
material having resilient qualities may be used in place of spring
assembly 50.
Top plate 54 and bottom plate 56 are typically relatively flat
plates attached to either end of spring member 52 and dimensioned
to fit within chamber 70 when spring assembly is placed vertically
in chamber 70. Plates 54 and 56 aid in keeping spring assembly 50
centered in chamber 70, provide a stable surface for supporting
cooling block 60 and product 72, and ensure that spring 52 delivers
a parallel force. Plates 54 and 56 may be constructed of any rigid
material such as cardboard, plastic, metal, wood, etc.
Top plate 54 typically includes a locating clip 58 extending upward
from its approximate center. Locating clip 58 is comprised of wire,
nail, wood, plastic or other material shaped to anchor cooling
block 60. In certain embodiments, block 60 includes a matching hole
(not shown) that fits over locating clip 58 when block 60 is placed
on spring assembly 50. In use, locating clip 58 aids in keeping
block 60 centered over top plate 54, particularly when container 10
is placed on its side. Bottom plate 56 is secured, using adhesive,
tape, glue, staples, tabs, or any other attachment means to bottom
of chamber 70.
Outer carton 80 of FIG. 1 is typically a corrugated box such as a
single or double walled corrugated box. Carton 80 includes
fasteners, such as tape or re-usable hook and loop fasteners (i.e.
Velcro), to counteract the force of spring assembly 50 and ensure a
tight seal between lid assembly 40 and body 20, particularly
between top panel 44 and side panels 32. Reusable Velcro fasteners
are advantageous because they tend to be effective even after
repeated uses, allowing re-sealing of container 10 after it is
opened.
When lid assembly 40 is placed on body 20 as shown in FIG. 2B,
upper cooling blocks 62 and restraint 46 enter product chamber 70
while top lid 42 mates with walls 24 of outer container 22 and top
panel 44 mates with side panels 32 of inner container 30. Gasket 38
aids in creating a seal between top panel 44 and side panels 32.
Closing and securing carton 80 with fasteners ensures a tight seal
between lid assembly 40 and body 20, particularly between top panel
44 and side panels 32. Optionally, fasteners on lid assembly (not
shown) are used to secure lid assembly 40 in place on body 20.
With lid assembly 40 in place and carton 80 secured, upper cooling
block 62 contacts the upper surface of product 72 and compresses
spring member 52. Compressed spring member 52 forces lower cooling
block 60 and product 72 toward upper cooling block 62 and ensures
secure contact between product 72 and blocks 60 and 62. Such
contact is maintained even as container 10 is shifted or placed on
its side and/or as cooling blocks 60, 62 shrink in size. Moreover,
even after a portion of product 72 is removed and container 10 is
resealed, spring assembly 50 forces lower cooling block 60 and
remaining product 72 toward upper cooling block 62 such that
remaining product 72 again is forcefully held between upper 62 and
lower 60 cooling blocks. Spring assembly 50 also serves to act as a
shock absorber, protecting product 72 and its packaging from being
damaged due to shock or vibration during shipping and handling.
As stated above, the shipping container of the present invention is
capable of maintaining tissues and other temperature sensitive
products at a temperature of -65.degree. C. or less for extended
periods of time. The vacuum panels 32, 34 and 44 of inner container
30 allow so little radiant thermal loss that the primary dry ice
mass loss is due to sublimation. This means that the shape of
blocks 60 and 62 shrink in a relatively dimensionally stable,
constant ratio manner, thus maximizing the contact area between
blocks 60, 62, and product 72, and maintaining the desired product
temperature.
One skilled in the art will appreciate that container 10 of FIGS. 1
and 2 is an exemplary embodiment incorporating various aspects of
the present invention, and the particular combination and
arrangement of the components is not intended to be limiting
thereof. For example, spring assembly 50 may be attached to lid
assembly or placed in container on top of one or more upper cooling
blocks 62. In such a configuration, placing lid assembly 40 on body
20 compresses spring assembly 50 and forces product toward bottom
of container (i.e. panel 34 and bottom lid 26). Alternatively, two
or more spring assemblies may be used on opposite sides of product
72.
Container 300 of FIG. 3 is another exemplary embodiment of the
shipping container of the present invention. Some of the components
of container 300 are essentially the same as container 10, however
container 300 includes a door assembly 310 for accessing product 72
and a second spring assembly 50 disposed between product 72 and top
panel 44. Container 300 does not include cooling block restraint 46
of FIGS. 1-2 as lid assembly 40 (i.e. top lid 42 and top panel 44)
is not removed to access product as in FIG. 2A. Rather, door
assembly 310 is attached to body 20 by straps, hinges or the like
such that door assembly 310 may be opened or removed from body 20
to access product 72. In the exemplary container 300, straps 390,
392 hingably attach door assembly 310 to body 20 and strap 396
removably secures door assembly 310 to body 20 when closed. One
skilled in the art will appreciate that a variety of means of
securing door assembly 310 to body 20 may be used in order to
facilitate opening and closing of door assembly 310.
Door assembly 310 comprised of door wall 330, which is similar to
side walls 24, and door panel 320, which is similar to side panels
32. In certain embodiments, door panel 320 has beveled edges 322
configured to mate with the edges of side panels 32 when door
assembly 310 is closed. Door panel 320 is dimensioned such that it
enters product chamber 70 and fits between upper panel 44 and lower
panel 34 when door assembly 310 is closed.
In an alternative embodiment of container 10 of FIGS. 2A-B,
restraint 46 is not used and lid assembly hingably attaches (not
shown) to body 20 like door assembly 300 of FIG. 3. In such an
embodiment, one or more spring assemblies 50 are oriented in
product chamber 70 orthogonally to the open end of body 20, similar
to the orientation of spring assemblies 50 in container 300 of FIG.
3.
It should be noted that while the exemplary containers 10 and 300
of FIGS. 1-3 are in the shape of a six-sided box, other shapes
and/or sizes may be used without departing from the scope of the
invention. For example, the container 10 may be in the shape of a
hexagon, octagon, rectangle, cylinder, sphere, ellipsoid, or any
other shape suitable for a particular application. Moreover, the
shape of the product chamber 70 need not correspond to the external
shape of the body 20 of the container, e.g. a container having a
rectangular body may include a cylindrical product chamber.
The following examples demonstrate the thermal performance and
efficacy of exemplary containers constructed and used according to
the present invention.
EXAMPLES
Three different types of tests were performed on exemplary
container 10 of FIGS. 1 and 2 of the present invention to determine
the ability of container 10 to safely maintain up to five pieces of
simulated frozen product 72 for an extended period of time. These
tests included a thermal bench test (FIG. 4), a cooler simulation
test (FIG. 5), and a drop and vibration test (FIG. 6). The methods
and results of each test are described in more detail below. In all
three tests, container 10 was arranged as shown in FIGS. 1 and 2,
including body 20 (having outer styrofoam container 22 and inner
vacuum panel container 30), lid assembly 40, spring assembly 50,
and shipping carton 80. Spring member 52 was a 0.135" (0.34 cm)
wire compression spring having an outside diameter of 4.25" (10.80
cm), a free length of 7.0" (17.78 cm) and a fully compressed height
of less than 1.0" (2.54 cm). Maximum compression load of spring 52
was approximately 14.5 lbs (6.6 Kg).
In addition to the three tests described above, a series of design
tests were performed to determine the effect of different
components of the container of the present invention. In
particular, these `design tests` examined the differential and
cumulative effects of a spring assembly (e.g. spring assembly 50),
vacuum panels (e.g. panels 32, 34 and 44 of container 10 as shown
in FIGS. 1 and 2) and/or periodic rotation on performance of a
conventional shipping container. Results of the design tests are
shown in FIGS. 7-10 and described in more detail below.
Essentially, the tests confirm that a shipping container
constructed and used according to the present invention yields
improved viability of frozen products for extended durations as
compared to conventional shipping containers.
The methods and sample results of each of the thermal bench tests,
cooler tests, shock and vibration tests, and design tests are
described in more detail in the following sections A-D,
respectively.
A. Thermal Bench Test (FIG. 4)
The purpose of the thermal bench test was to simulate and evaluate
the performance of a shipping container of the present invention
when product is shipped but not used by the customer and returned
to stock. In such situations, product would be acceptable for
restock if the design of the container were suitable for
maintaining frozen product for extended periods, e.g. 72 hours or
more, and if the container had not been damaged or opened. During
the test, a minimum of two containers, similar to container 10,
were placed inside an environmental chamber `incubator` and tested
to determine the time required for the product to reach its maximum
specified temperature limit, generally -65.degree. C. The first
container contained one piece of simulated product and the second
container contained five pieces. Three blocks of dry ice were used
in each container, one below the product and two above, as shown in
FIGS. 2A and 2B. A total dry ice weight of 3.6 Kg was used in each
container (approximately 10% below a preferred minimum weight of
4.0 Kg). The containers were subjected to a shipping profile as
outlined in Table 1.
TABLE 1 Thermal Bench Test Parameters In-Bound Out-Bound Shipment
Dr.'s Office Shipment Simulation Simulation Simulation Transit 24
hr. Shipment 24 hr. hold 24 hr Ship- ment, test to failure
Orientation Rotate box every 4 hr. .+-. Upright Rotate box 1 hr.,
dice method every 4 hr. .+-. 1 hr., dice method Incubator
38.degree. C. .+-. 3.degree. C. 25.degree. C. .+-. 3.degree. C.
38.degree. C. .+-. 3.degree. C. Temp.
One calibrated thermocouple probe was placed in the first shipper
and three thermocouple probes were placed in the second shipper
(within the top, center, and bottom simulated product pieces) to
measure temperature of the simulated products. The probes were
placed inside a media pouch of the simulated products. The
incubator had at least two thermocouples to measure temperature of
the simulated external environment.
The "dice method" of Table 1 above, refers to a method of labeling
each container in a fashion similar to a six-sided playing die. The
labeling of the containers in this fashion facilitates the rotation
and tracking of the shipping container sides during the tests.
During the thermal bench test, the cooler test, and the vibration
test, the simulated product temperatures were required to be below
-65.degree. C. for at least 72 hours. Transient temperature
excursions above -65.degree. C. were deemed acceptable so long as
exposure to room temperature did not exceed 15 seconds. All
environmental temperatures were required to be within .+-.3.degree.
C. of their set point during steady state.
FIG. 4 shows the results of a representative thermal bench test of
a container according to the present invention having one piece of
simulated product as measured by a thermocouple. Product
temperature in 0.degree. C. is represented as a solid line. Product
temperature was maintained below the target temperature of
-65.degree. C. for more than 120 hours, far exceeding the required
`return to stock` time of 72 hours.
B. Cooler Test (FIG. 5)
The purpose of the cooler test was to simulate and evaluate the
performance of a shipping container according to the present
invention when a product is shipped to the customer and the
container is used as a cooler to store the product, for example in
a doctor's office. During the test, a minimum of three shippers
were placed inside the environmental chamber `incubator` and tested
to determine the time required for product to reach its maximum
specified temperature limit (e.g., -65.degree. C.). Each container
contained five pieces of simulated product. Calibrated
thermocouples were placed in the product and the incubator as
described above. The containers used in the cooler test were
similar to container 10, and were subjected to a shipping profile
as outlined in Table 2.
TABLE 2 Cooler Test Out-Bound Shipment Dr.'s Office Simulation
Simulation (Cooler Test) Test to Failure Transit 4, 24, 48 hr
shipment Dr.'s office, 68, 48, 24 hr times hold cooler minimum
times. Orientation Rotate box every 4 hr. .+-. Upright 1 hr., dice
method Incubator 38.degree. C. .+-. 3.degree. C. 25.degree. C. .+-.
3.degree. C. Temp. Pull Pieces None 1.sup.st piece at end of
transit time, last at failure. Pieces 2, 3 and 4 must have a
minimum 4 hr interval between removal.
FIG. 5 is a graph showing results of a representative cooler test.
Samples 2, 3 and 4 (not shown) were removed from the container
between 4 and 64 hours, with at least a 4 hour interval between
each removal. The temperature of Sample 1 (thick broken line)
increased when removed from the container at 64 hours. Sample 5
(thick solid line) remained below -65.degree. C. for over 123
hours, even with the periodic opening of the container and removal
of simulated product.
C. Drop and Vibration Test (FIG. 6)
The purpose of the drop and vibration test was to verify that the
integrity of the product and its packaging is not damaged by shock
and/or vibration during shipping and handling of a container
according to the present invention. For this test, two shipping
containers were tested for shock and vibration per the
International Safe Transit Association (ISTA) standards (ISTA 1A
and 1C ). The first container contained one simulated product piece
and the second contained five pieces. The temperature of at least
one piece of simulated product was monitored as described above.
The testing profile is outlined in Table 3.
TABLE 3 Drop and Vibration Test Shipping Parameters Out-Bound
Shipment ISTA Shock and Vibration Simulation Test Transit 24 hr.
Shipment Performed between 24 and 72 hr Orientation Rotate box
every 4 hr. .+-. 1 Per ISTA Test hr., dice method Incubator
38.degree. C. .+-. 3.degree. C. Per ISTA Test Temp.
Following the test, the containers were opened after failure (96+
hours) and inspected for damage to the container and/or the
simulated product. No such damaged was found. As shown in FIG. 6,
the temperature of one of the product remained at or below
-65.degree. C. for over 128 hours during the test.
D. Design Tests (FIGS. 7-10)
As mentioned above, several variations of a shipping container of
the present invention were tested for their ability to maintain
five pieces of simulated product at a temperature of -65.degree. C.
or lower for an extended period of time under a number of different
conditions. In particular, these `design tests` examined the
effects of vacuum panels, a spring assembly, and periodic rotation
or movement of a container. For each test, a thermocouple probe was
placed within each of the five pieces of simulated product. During
testing, each container was maintained in an incubator at
38.degree. C..+-.3.degree. C. The results of each design test are
shown in FIGS. 7-10, where the temperature of each simulated
product is represented by a separate thick solid line. Each graph
includes a notation of the elapsed the time when a first product
exceeded a temperature of -65.degree. C.
Design Test 1: Conventional Shipping Container
FIG. 7 shows the temperature of simulated products in a
conventional shipping container laid on its side, with no spring
assembly and no vacuum insulated panels. One piece of the simulated
product exceeded the target temperature of -65.degree. C. after
only 24 hours in the conventional shipping container. The last
piece of simulated product to exceed -65.degree. C. did so after
approximately 42 hours.
Design Test 2: Effect of Periodic Rotation
FIG. 8 shows the temperature of simulated products in the
conventional shipping container as in Design Test 1, however the
container was periodically rotated throughout this test, for
example at 20 hours, 24 hours, 42 hours, 46 hours, and 50 hours.
All pieces of the simulated product remained below -65.degree. C.
for approximately 50 hours, indicating that periodic rotation
increased the performance of the conventional container for
maintaining frozen products.
Design Test 3: Effect of Spring Assembly
FIG. 9 shows the temperature of simulated products in a container
similar to the conventional container used in Design Tests 1 and 2,
however the container used in Design Test 3 also included one
spring assembly according to the present invention. As in Design
Test 1, the container remained on its side for the entire duration
of the test. As shown in FIG. 9, all products remained at or below
-65.degree. C. for at least 70 hours, with a maximum duration of
approximately 80 hours. Thus, the spring assembly of the present
invention dramatically improved the duration of effectiveness of
the container by approximately 46 hours (e.g. from a minimum of 24
hours in Design Test 1 to at least 70 hours in Design Test 3).
Design Test 4. Effect of Spring Assembly + Vacuum Panels
FIG. 10 shows the temperature of products in a shipping container
having both a spring assembly and an inner container of vacuum
panels according to the present invention. The temperature of the
products, again shown in thick solid lines, remained at or below
-65.degree. C. for at least 87.5 hours with the container resting
on its side. At 91.5 hours, the shipping container was rotated to
upright, resulting in decreased temperatures in all products and
further extending the duration below -65.degree. C. to
approximately 110 hours. Thus the combination of a spring assembly
and insulated panels according to the present invention further
increased the effectiveness of the container as compared with the
spring assembly alone. Additionally, the decreased temperatures
with rotation of the container suggests that periodic rotation or
movement further increases the time that products may be maintained
in such a container.
While the invention is susceptible to various modifications and
alternative forms, specific examples thereof have been shown in the
drawings and are herein described in detail. It should be
understood, however, that the invention is not to be limited to the
particular forms or methods disclosed, but rather the invention is
to cover all modifications, equivalents and alternatives falling
within the spirit and scope of the appended claims.
* * * * *